Grinding machine



Jan. 3o, 1945.

L.\ E. MEHLHOPE ET AL GRINDING MACHINE GVSheets-Sheet l Filed March 29 1943 Jan. so, 1945.

. L. E. Ml-:HLHOPE ETAL- GRINDING MACHINE Filed March 29 1943 6 Sheets-Sheet 2 Jan. 30, 1945. L E. MEHLHOPE Erm.'

GRINDING MACHINE Fild March 29 1943 6 Sheets-Sheet 3 n UNH Jan. 30, 1945. L. E. MEIy-ILHOPE ETAL GRINDING MACHINE 6 Sheets-Sheet 4 Filed March 29, 1945 W H.. m 4 n O J P A 0 u c ha MNWI; 40W/ w 4 Y ksksnhw vNvNUIINW Jan. 30,1945. v L. E. MEHLHOPE ET'AL v 2,368,315

GRINDING MACHINE Filed Marcn'ze, 1943 e sheets-sheet 5 ATTO NEY.

Jan. 30, 1945.

L. E. MEHLHOPE' ETAL GRINDING MACHINE Filed Mawh- 29, 194s s sheets-sheet e A Tpo/M55? Patentes Jan. 3o, 1945 Lincoln E. Mehlhopeand EdgarvD. Vancil, Cinn cinnati, Ohio, assignors to The Cincinnati i Milling Machiney Co., Cincinnati, Ohio, a corporation of Ohiol Application March 29, 1943, Serial No. 481,036.

vclaims (01."51-3) This invention relates to machine tools and more particularly to improvements ingrinding machines.

One of the objects of this inventionl is to'provide an improved machine for performing cylindrical grinding operations on work which cannot be conveniently Supported on'centers'in con? ventional grinding machinesbecause of its shape or construction. x H

Another object of this invention is to provide a grinding machine which is organized to receive a work shuttle and rotatably drive it in precision relationship to a grinding wheel so that a cylindrical surface on a Work piece held by the shuttle may be accurately ground.

-A further object of this invention is to. provide a grinding machine with regulating wheel driving means -for a work supporting shuttle, together with auxiliary means for grinding or truing Said wheels in situ.

This is accomplished by forming-centervholes lin the ends of the work'to define the axis and I'tionshave to be performed tation.

on cylindrical surfaces which formpart of awork piece which is of such an odd shape .that it does not -prov1de its' own' centers vvupo'n Awhich `it may be rotated,v and therefore cannot 'be supported inthe con.` I ventional center type grinding machine.

In the metal-working industry itis common practice in forming or producing cylindrical surfaces to support the work for rotation about an axis whichfwill generatefthe desired surface.

to he utilized in supporting the Work during ro'- vThe shape of some, work, however, is such as to prohibit this practice, usually because 1 they do not provide the necessary surface in Still another object of this invention is to provide a grinding machine with .meansfor' performf ing a cylindrical grinding operation and auxiliary means for' performing a. supplementary grinding operation in one setup of the work piece.`

Other objects and `advantages of,l thepresent invention Should be readily apparent by reference to the following speciflcationconsidered in conjunction with the accompanying 1 drawings forming apart thereof and it is to be understood that any modifications may bemade in the exact structural details there shown and described, within the scope of the appended claims, without departing from or exceeding the spirit ofthe in-4 vention.

Referring to the drawings in which :like feference numerals indicate like or similar parts:

Figure 1 is a front elevation of a machine tool. embodying the principles of this' invention.

Figure 2 is a side elevationfof the machinev shown in Figure 1. l Y,

Figure 3 is a plan view partly insectiongshowing the relationship of lthe work holdingA and driving mechanism. -K

Figure 4 is a sectionin velevation on the line 4- 4 of Figure 3.

Figure 5 is an enlarged detailsection 5 5 of Figure 1.

on theline Figure Gis a section on the line 6--6 of Figure 5.

Figure '7 is a detail view onV theline 'I-l ofy Figure 4. v y l Figure 8 is a diagram of the hydraulic control,

circuit for the machine. It often occurs that cylindrical grinding opera-i on the work.

which the holes may be formed.l Thereforev other means must be resorted to in order to support the work for rotation' about the vdesi'redgenerat- In the present instance, the work is mounted in' a shuttle which has a pair'of spaced journals wherebyit may Ibe supported yfor rotation and the axis of these journals determines the generating axis. The work is secured -in the shuttle in suchposition that the'axis of the surface to be generated is co-incident withthe axis of rota-- tion ofthe shuttle. vObviously considerable time is involved in performing this operation and Where several machining operations are to be performed, it is desirable that the work'remain inthey same shuttle and the shuttle transfer-red fromA one machine'. to another, thereby insuring t greater accuracy andA coordination` between the several'machining operations as well'as the savn ingintime. Y v ,f ,I

Thepresent machine is so contrived'and designedy that it may receive these shuttles andv utilize them .for rotating work contained therein in performing a'cylindrical grinding -operation In general, the machine comprises va bed It which is somewhat L-shaped and one portion of the bed is provided with a pair of guideways I l d and lI2 as shown in Figure 2 for supporting a slide I3 which carries a grinding wheel I4 that is capa- A ble of two-directional movement. The other pore tion I5 ofthe bed is utilized for supporting and driving a removable shuttle, indicated generally" 59 by the freference numerall Ihand shown more particularly in Figure 3. The grinding wheel is' supported on a cross slide IB which, in turn, is

supported in guidevvays4 I'I ,and l'formed in the.

slide I3v for cross movement relative thereto. A prime mover I9 ymounted. fonwthe'v'ls'lide I6' as,

shown in Figure 2 is connected by a suitable belt 20 for driving the grinding Wheel i4.

Since the shuttle is removable it is necessary to provide separable bearing means whereby the shuttle may be placed inthe bearing and then the bearing closed to hold it in a ixed rotatable position while poweris applied toit to effect the rotation.

As more particularly shown in Figure 3, the

shuttle I6 is provided with spaced journals 2l and 22. The shuttle itself constitutes no part of the present invention, but to facilitate understanding of this invention itmay be said' that the work piece, which is indicated by the reference numeral 23, is secured in the proper position within the shuttle by three sets of clamping members indicated generally by the reference numerals 24, 25 and 26 which are spaced longitudinally of the shuttlein the most advantageous lpositions to hold the work' rigid with the shuttle Wherebyany rotative'movement imparted to the shuttle Willfimpa'rt rotation to the Work. The reference Vnumeral 21- indicates generally the cylindricalfsurfaceonthe-work piece which is to be ground by? the-grinding Wheel I4.

`Since-the grinding=wheel I4 must be reciprocatediinord'er' toj'grind the surface 21it will be obvious? thatjthe'shuttleflG must beV supported for'rotationfaboutan axis Vparallel tothe axis ofthe guideways I'Ifandf l2 upon which the slide |3- moves toeiTect'ireciprocation of the grinding wheel.

To `thisfendjthe portion I5 ofzthebed is provided witha pair-of 1 support' rollers 28 which are properlyfspacedntof. engage the journals 2i and'. 22. YThese rollersare rotatably supported on a. pillow b1ock29which is. adjustable. and which mayebe clamped .inA adjusted: positioniby azplurality of clamping bolts 30 passing through elongatedrslotsf'30' in the pillowblock.

. In addition, the V pillow-block may ber positively held byrapair of adjustablebacking-up screws 3|. AThese screwseserve to square up the. pillow block-and:insure that the'rollers are aligned in parallelism'fwith the guideway Il. The shuttlef I6 is also he-ldin-position-'by a pair of regulatinglwheels 32 which also" engage the journals and these wheelsgare supported on a shaft 33 which has a-driving` pulley'34 secured toV oneen'd thereof. This pulley 'is operatively connected by a seriesof belts 35.-toa drivemotor 36` mounted on an- :adjustable basef31locatedjin the bed of the machine asl shownl itx-.Figure 2.

The regulating ordrivingwheels' 32v drive the shuttle I6 by friction and therefore it is necessary tol-.hold the shuttle against any lateral movement during rotation'and alsotoinsure that the axis; of -rotationof the -'work doesV not shift which, ofcourse, lwould lresult in eccentricities in 'to the right hand end of the cylinder 52 that the crank 42 will be rotated in a clockwise di- 1 rection, removing the rollers 38 :and 39 from engagement with the shuttle. Similarly, when pressure is admitted to the left end of cylinder 52 the'rollers willrmove in a counter Clockwise directionY into engagement with the shuttle and thereby-hold it into frictional engagement with the regulating wheels 32 for actuating purposes.

Since the surfaces of the support rolls 28 must be carefully protected, means have been provided for lifting the shuttle olf of these rolls when the shuttle is to be. removed, and for receiving and supporting the shuttle when it is inserted in the machine so as to prevent any denting or attening of the rollersurfaces which might interfere with the concentric rotation of the shuttle. This meanscomprises a pair of lift rollers 54 and 55 which are so spaced and positioned as to engage the peripheral surface 56 of the shuttle which is between the journals 2l and 22. In addition, the pillowbloclr-ZS)v is provided with a pairof receiving pads v5Eiand 51 which arcadjustably mounted in position and clamped as by bolts58.

4These pads, it will .be noted from Figiue 4, are located above the. rollers 28 in such position that when the lift rollers 54 are rotated about the pivot. shaft 58 after the clamp rollers 38 have been removed, theshuttle will be rotated olf of the support rollers 28.:arid onto the pads 56. The lift rollers are oscillated in a clockwise direction to eifectthis and they remain in position While the shuttle is removed and a new oneplaced in position. This insures that` the shuttle is properly supported before itis lowered onto the support rollers 28.

The lift rollers 54 are carried by a crank 60 which is operatively connectedby a pin 6l anda connecting link 62 to the rod 41 which hasa bifurcated lmember 53 integral therewith for connection by pin B4-to the link. It will now be obvious that-the. lift rollersv 54 will move simultaneously with the clamp rollers 38 in a direction to lift the shuttle after the clamp rollers are removed, and to lower the shuttle before the clamp rollers move into clamping position.

It is, of course, necessary to hold the work holder or'shuttle against axial movement during the grinding operation and to this end the shuttle is provided with anges 65 and 6B located adjacent the ends of the journals and the various sets of' rolls for supporting and driving the shuttle are so spaced as to cooperate with these flanges in holding the shuttle against axial movement. When the shuttle is lowered into the machine as by a crane or the like, itis necessary. to axially position the shuttle while on the supporting pads and lift rollersso thatwhen it is lowered onto the support rollers it will be in the proper position. This is accomplished by pro- I viding the-shaft' 61 which supports the rollers 54 The crank andthearms-` are supported'. for yrotation on .a shaft45 vand .the crankris connected to anpperatingjpinl which-is carried byvv a reciproca'blero'd '41. `The. pinhhasa square block 'vmounted` on it which ts in the bifurcated end This eliminates the necessity vfor any .axialy tion, and this means comprises a pair of grindf ing wheels 69, Figure 3, attached to opposite ends of a shaft 10 journaled in a housing 1I.v This shaft has a drive pulley 12 which is connected by a belt 13 to a pulley 14 attached to the armature shaft of an electric motorv 15. l

These parts are all mounted on a slide-16 which may be adjusted toward and from the regulating wheels by a hand wheel 11 shown in Figure 2. The slide 16 is in'turn supported upon a longitudinally movableslide 18 which may be moved by a hand wheel 19. The grinding wheels may The'reversing valve has a ypair Vof ports ||2 and I|3 which are connected .bychannels ||4 and I |5to ports |||A andl |1 of theypilot valve When vthe pilot vvalve shifts, it serves to.

alternately connect these ports toa return port I|8 whereby the, uid may flow through channel ||9 and rate valve |20 to a return line |2I, terminating in reservoir 89. Thus, vthe rate of movement of the slide I3 is controlled by throttling the exhaust lfluid fromeither .end ofthe cylinder 82. f f

The pilot valve has an enlarged spool |22 which is movable relative to the pressure port |02 l whereby after the spool passes the Acenter posibe trued by truing diamonds'80 which are ad- Y justably mounted on the housing 8| which supports the shaft for the regulating Wheels. Thus the regulating wheels 32 may be trued in situ. 'Ihe slide |3 which carries the grinding Wheel is operated and controlled by a hydraulic transmission whichis diagrammatically illustrated in Figure 8 f lThe transmission comprises a cylinder 82 which is attached to the underside ofthe slide" I3 and a piston 83 which has piston "rods 84 and 85 extending through opposite-ends ofthe `cylinder and connected to the bed of the machine. Since the cylinder is the moving member, theA uid pressure is conducted to lopposite ends thereof throughthe piston rod. y

The opposite ends ofthe cylinder areconnected to a reversing valve 86 which has a pressure port `81 that is supplied from a pump 88 that draws fluid from a reservoir 89. ,A pair of motor ports 90 -and 9| in the reversing valve are connectedA by channels 92 and 93 to opposite ends of the cylinder, these lines extending through a start and stop valve which is indicated in sections in Figure 8. r Y

The sections 94 and 95 o'f the start and stop valve control the alternate connections of lines 92 and 93 either to the cylinder inthe start position, or to the lines 96 and 91 in the stop position of the valve, the latter lines' being con--v The reversing valve 86 has a plunger 00-which is .hydraulically positioned in either one of two positions by a pilot valve |0I. This valve has a pressure port |02 and a pair of ports |03 and |04 which are respectively connected to opposite ends of the reversing valve through tarry valvesv |05 and |06 respectively. i l i The pilot valve plunger |01 is operatively connected to a trip control .rod |08located on the front of the bed as shown in Figure 1 and kadapted to be red by suitably formed dogs |09 and .I l0 mounted on the slide I3. The rod may r also be operated manually by means of the handler formed integral therewith.

tion the fluid pressure will act to complete the shifting of the plunger and thusy act asa detenting mechanism. Y f n The channels.' |23 and |24 whichvconnectthe tarryvalves |05 and |06 to the ports |25 and. |26 in the opposite ends .of the reversing valve for shifting the plunger thereof have lserially arranged check valves |21 therein which vblock the return flow from one-end of the valve-when the other end is under pressure and thereby cause the opening of by-pass'valves |28 which are connected in parallel with the check valves y|211 whereby, Whenthe lay-pass valves` |28y open, the respective line is connected to the return line I2,| and thereby by-pass the tarry valve.

The by-pass valves |28 are normally held closedv vwith an operating lever |30, thus affording manual operation of the'valve. While the ytable is in motion it may be automaticallyreversed by properly setting trip dogs |09 and ||0`fwhich operatek in conjunction with thetrip plunger |08. Also,

on the front of the machine are thecontrolknobs .|3|, 4|32 and |33 .which are utilized for adjusting the setting of the tarry. and rate valves. When the lever |30 is thrownr to a'stop position the motor channels are. automatically connected to the servo-control valve 98 whereby manual servocontrolof thetable is obtainable at all times while the table is stopped.,

Thecrossslide |65 has a depending nut |34 in which is threadeda cross feedscrevv' |35, Figure l2,.Which is operatively connected by gearing |36 toa shaft |31'havingfa hand wheel |38, Figure 1. By rotation of the hand wheel the cross slide may be manually adjusted.- The hand wheel |38 has anelyk ytoo-thed'periphery which is engageable by apick feedpawl |39 which is oscillated bya piston |40, Figure 8, slidably mounted in a cylinder I4 I. The piston has arcuate notches |42 formedlthereingwhich are interconnected by a ridge |43. A lever =|44is pivotally mounted on f a pin |45 in such position that a roller |40v will engage the notches |42. As the piston is'reciprocated the roller rides over the ridge I 40 and thereby rocks the lever |44 and this lever is operatively connectedto impart an oscillatory motion to the pick feed pawl |39 and thereby produce small `inieed movements lof the grinding wheel.

The piston |00 is actuated at each reversal of y the table and' therefore suitable connections are madev'whereby Whenjthe 44Vtable isreversed the pis-- to'n |40: is actuated. This.l is accomplished' by connectingthe 'ports' |03: and |04 of the table pilot valveV to branch lines |41 and |48 which lead to portsy |49 and |50 oflth'eitable selector valve. When'the lp1unger1991of this valve is rotated to effect powerV reciprocation of the table, cross bores and`|52 in'plungerz99 connect ports |49 and |50 to ports |53 and |54. Lines |55 .and |56extend fromV these ports to ports |51 and |58 of a pick feed selector valve |59 which has a rotatable plunger |60 and is shown in six sections. This plunger terminates in an operating knob |6|. located on the front of the machine as shown in Figure l. clockwise from the position shown, arcuate grooves |6| `and |62 connect channels |55 and |56 to channels |63 and |64 which terminate in opposite ends of the cylinder |4|. Thus, upon each reversal of the pilot valve the piston |40 is shifted and for each shifting movement, the lever |44 is rocked to cause oscillation of the pick feed pawl.

There may be 'cases Where it is desirable to infeed the grinding wheel without reciprocation of the table, and means are provided whereby this may be done automatically. To this end the channels' |63 and |54 are branch connected to ports and |86 of the valve |59, and by meansA of arcuate grooves |61-v and |68 these ports are connected to channels |69 and |10, which lead tion atwhichtime the automatic -hydraulicfde- It will thus be apparent that by means of l the pick feed selector valve the pick feeding may When this valve is rotated v to a pair of ports |1| and |12 of a pilot valve |13 and also in parallel relation to a pair of ports |14 and |15 of a reversingvalve |16.

The valve |16 hasa pressure port' |11 and the valve |13 has apressure port-|18 andthese two pressure ports are connected by a common channel |19 to port |80 of thepick Jfeed selectorfvalve. This port is connectible by an annular groove |8| in plunger |60 to a'pressure port |82 which is directly supplied by the pump 88.

The'valve |16has a pair of ports |83 and |84 which are alternately connectible to the pressure port |11 by the valve plunger |85. 'The port |83 is directlyconnected by channel |86 to port |81 located in one end of the valve |18 for shifting the plunger |88 thereof in one direction. The

` port |84 is connected'to'a port |89 of valve |18 ment of plunger |88 in one direction, but when pressure is admitted to port |81 the groove-acts as a throttle to control the rate of escape from port |89 to exhaust.

The grooves |9| and |92 in the plunger |85 serve to connect the ports |83 and |84 to exhaust ports |93 and |94 respectively. Between these grooves is an enlarged spool |95-which serves to complete theshiftingof the plunger after it passes the'pressure'port |11 in either direction and'this servesj as an; automatic detent mechanism. L

As the plunger v|88 shifts it alternately connects the pressure port |18 toports |1| and |12 to cause-actuation of the pick feed plunger and when the plunger has completed its movement the pressure rises in the respective channels and thereby at either port |14 or |15 of valve |16 to shift either plunger' |96 or |91l against the resistance of a spring |98`ar1d4 thereby cause movement of plunger |85 until'it'has passed the'center posibe placed under control of the table reciprocating mechanism or may be intermittently and automatically elected without reciprocation of the table.

As shown in Figure 8, a suitable rotary reverse control valve |99 having an operating control lever 200 has connections 20| and '202 to the pump88' and the reservoir 89 respectively for controlling actuation of the piston 5| in the cylinder 52 which actuates the work shuttle lifting and clamping mechanism. This control may be mounted on the bed as more particularly l shown in FiguresV 1 and 2. n

Attention is invited to the fact that whenV the table start and stop valve is moved to a stop position that pressure and exhaust connections are automatically established with the table servo-motor control valve 98. In other words, the selector valve plunger 99 is provided With a groove 203 for connecting the pressure port 204, which issupplied directly from the pump 88 through channel 205, to a port 206 which is connected by channel 201 to the servo-valve 98.

This serves to eiect engagement of the hydraulc clutch which is shown more particularly in Figure 6 and which serves-to operatively connect the hand wheel 208shown in Figures 1 and 2, tothe servo-valve 98. As shown in Figure 8 the servo-valve has apressure groove 209 which is directly connected by a branch 2|0 to the pump supply line 205. This groove terminates in two pressure ports 2|| and 2|2 in the valve sleeve 2|3 in which is slidably mounted a .pair of valve pistons 2|4 and 2|5. This sleeve also has a pair of ports 2|8 and 2|9 which are the Ytermini of lines 96 and 91 on the selector valve. There is also a pair of exhaust ports in the sleeve which are connected together to line 220 which leads to the reservoir. Y

As shown in Figure 5 theservo-valvel block 98 Ahas an integral reduced portion 22| by which it isrotatably supported in the housing 222. A pinion 223 is attached to the end of theportion 22| for i'ntermeshing with a rack 224 attached to the underside of the slide i3. This forms a mechanical feed back connection to the servovalve. The hand wheel 208 is mounted on the end of a, shaft 225 which carries a sprocket 226 operatively .connected through sprocket chain 221 to a sprocket wheel 228 attached to the shaft 229. 'Asshown in Figure 5'the shaft 229 is operatively connected through a gear 230 and -a gear couplet 23| to an internal ring gear 232 formedintegral with the clutch member 233. The cooperating clutch member 234 has a plurality of pistons 235 which `are urged outwardly by hydraulic pressure into engagement with the flange 236 lof the clutch member 233. The clutch member 234 carriesI a pin 235 whichis interposed between the plungers 2|4 and 2|5.of the servovalve. `It will be noted that each of the valve plungers 2|4 and 2|5 have interdrilling 236' by which the `pressure Vin the annular groove 231 is communicated to .the end chamber 238.

'Ihispres'sure-would be Vthe same as the pres-l 'sure infopposite lendsrof the tablecylinder when the servo-valve is connectedforroperation and ,y serves to urge or maintainthe plungers 2I4 and the tablewill'fcause-,a feed back connection' through the rack and pinion 224, 223 to effect rotation of the servo-valve block 98 in a direction to follow up the movement of the pin. 235

and thereby recentralize the servo-valve.

An auxiliary grinding attachment has been` provided onthewheelhead slide I6 and comprises an independent slide 239 which is adapted to be moved by a hand wheel 240 through a conventional screw and nut mechanism. 'I'his slide has a depending bracket 24| for supporting an auxiliary grinding wheel V242 which may be utilized tovgrind a groove 243 in the work piece which is more particularly shown in Fig' ually as by the servo-motor control mechanism" to align the grinding wheel 242 with the groove 243 and thenl the hand wheel 240 maybe rotated to feed the grinding wheel into the work.

If so desired, the usual backrest 241 may be provided for supporting the free end of the work during the grinding operation.

There has thus been provided an improved grinding machine for grinding special work piecesl rotation-the combination of a grinding wheel supported for axial reciprocation vand lateral feedingv movement, means for supporting the shuttle for rotation about an axis parallel with the axis of rotation of the grinding wheel,.means forv initiallyl receiving said shuttle including a pair of rollers, means associated with said rollers for engagement with said shuttle for axially po ing and "rotating means.

sitioning the shuttle with respect to the plane of rotation of the grinding wheel, additionahrollers f for supporting ya rotating shuttle during a grinding operation, and means to actuate the first pair of rollers to transfer the shuttle to said support- 3. In a grinding machine for-grinding cylindri` cal surfaces on centerless work pieces equipped with'shuttles to form rotatablefsupporting means, thev combination of a bed having a grinding wheel supported thereon for rotation and axial reciprocation, the combination of a pair of support rollers mounted on the bed for rotation about an axis parallel to the axis of the grinding Wheel, a pair of driving rollers, a lpair of clamping rollers for holding the shuttle in engagement with the previous rollers during rotation f the shuttle, a pair of lift rollers mounted on the bed for bodily movement in a direction to lift the shuttle from the support rollers, and power operable means for shifting the clamp rollers and the lift rollers.

4. In a grinding machine for grinding an external cylindrical surface on a work piece equipped with a shuttle for rotatably supporting itwith the surface to be ground projecting beyond one end of the shuttle, the combination of a bed, aslide reciprocably mounted on the bed,v

a hydraulic control circuit in the bed for reciprocating said slide, a wheelhead reciprocably mountedy on the slide, means on the bed lfor rotatably supporting and clamping the shuttle for rotation about an axis parallel to the axis of the grinding 'whee1, said means including a pairof support which do not have means for self-support and therefore must be provided with their own special nxtures by which they maybe supported for rotation.

What is claimed is:

1. In a machine for grinding cylindrical surfaces on an unsupportable centerless work piece requiring a `shuttle having spaced journals for supporting it for rotation, the combination of a bed, means on the bed engageable with the journals for .supporting and driving said shuttle to effect rotation thereof about an axis coincident with the axis of the surface to loe formed on the work, said supporting means including a pluraility of sets o-f rollers circumferentially spaced about the axis of said shuttle, said sets of rollers comprising a first set* of support rollers and a second set of drive rollers circurnferentially posi- -tioned to entirely support said shuttle, an additional set of rollers 'located intermediate said pairs of rollers for lifting the shuttle from the rst two pairs of rollers, and means mounted on the bed for receiving said shuttle including a pair, of support pads mounted on the bed.

2. In a grinding machine for grinding cylindrical surfaces on centerless work pieces equipped With shuttles whereby they may besupported for rollers mounted on the bed, a lpair of driving rollers, power operable means for actuating said rollers and including a start and stop control, means to receive said shuttle upon insertion in the machine including a pair of landing surfaces and a pair of receiving rollers, power operable means for actuating said receiving rollers to transfer Ithe shuttle to the support and driving rollers, a pair of clamping rollers for securing the shuttle `against axial or` lateral movement during rotation of the shuttle, uid =operablemeans for shifting the receiving rollers and clamping rollers anda control for causing simultaneous actuation thereof.

5. In a grinding machine; the combination with a bed having means thereon for rotatably supporting a work piece, of a reciprocable slide mounted on the bed for movement parallel to the axis of rotation of the work piece, a cross slide mounted on the reciprocable slide, a grinding wheel supported forrotatlon on the cross slide, power` operable means for actuating the reciprocable slide and feeding the cross slide toward `the work t0 effect a cylindrical grinding operation thereon, an auxiliary slide mounted on the cross slide, a formed grinding wheel supported for rotation on'the auxiliary slide, and

.means te feed the auxiliary slide independent means thereon for rotatably'supporting and drlvingva Work piece, of a, grinding. wheel, aicross slide for supiportingthe `grinding Wheel,` power operable means for eiiecting relative reciprocation betweenthe grinding wheel and the Work to effect a reciprocating grinding cyole, and .means for effecting aninfeeding formed grinding operation on the work including an auxiliary slide mounted on the erossslide, a grinding Wheel ro'- tatably mounted on the auxiliary slide, separate power operable means on the auxiliary slide for driving the grinding Wheel thereof, and manually operable means to etiect infeeding of the auxiliaryslide relative to the cross slide.

'7.-A machine for grinding external cylindrical surfaces on portions of oenterless Work pieces requiring a.` supporting shuttle, said work being clamped in the-.shuttle with the. portion to be ground projecting beyond foneendlthereof; having: -in combination .abed, .longitudinal guideways formed on a. portion of said bed, a vpair-of supers imposed slides mounted ,on .said guideways i and carrying ay grinding wheel, means :on one fof the slides for-driving said grindingwheeLvsaid shuttle having spaced journal portions thereon,`means.

on the bed adjacent .said j guidevvav` portionen.- gageableiwith saidvjournal portions for positioning said shuttle to place thefwork portion tobe ground-in front of saidV grindingiwheel, power operable means :for rotating said shuttle, power operable means for reciprocating said grinding wheel slides and pick feedmechanism for feeding the grinding Wheel toward the -`Work.

LINCOLN- E. MEI-IM-IOJPE.'`

EDGAR D. VANCIL. 

